The International Organisation for Migration said the rate of arrivals had dropped in the first week of April, with 5 April the first day since last year that no arrivals were recorded.

More than a million undocumented refugees and other migrants have entered the EU by boat from Turkey to Greece since early last year, generating an unprecedented crisis for the EU's 28 member-states.

A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries such as Syria, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.